Okay, so I'm using a new MacBook Pro to do streams on my Twitch channel. That being said, I followed a Youtube video months back, when I first started on how to get my desktop audio through OBS. I did everything the video said and for a good amount of time everything was all good. Somewhere down the line the multimedia output that i selected in my sound preferences which was created after instaling soundflower was what i would select to get sound through OBS and still be able to hear everything through my scarlet 2i2. There was one time it just stopped working and I only heared audio if I selected the scarlet. I didn't pay no mind to it and idk what happened exactly, but it fixed itself. So I went back to the streams and today my computer overheated, froze all up and I restarted it. Uppon it booting back up the multimedia-output was not working or so I thought. Turned out the stream could still hear the desktop audio, but for some reason it wouldn't play it through my scarlet, so I could NOT hear what they were hearing. I'm sure there's a fix for this somehow. I just dont know enough to fix it myself. Please, can anyone help me out here?
While I don't fully understand what you're doing and what goes wrong I can't tell you how to configure Sound Flower the right way. But I know an alternative solution.
Using Audio MIDI Setup, to send Audio to multiple devices:
Your Mac has Audio MIDI setup installed by default. By selecting the + and choosing 'Create Multi-Output Device' you can send audio to both your headphones and to soundflower (which sends it to OBS if I understood you right).